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Commit cf437426 authored by Eric Paris's avatar Eric Paris
Browse files

inotify: do not BUG on idr entries at inotify destruction 



If an inotify watch is left in the idr when an fsnotify group is destroyed
this will lead to a BUG.  This is not a dangerous situation and really
indicates a programming bug and leak of memory.  This patch changes it to
use a WARN and a printk rather than killing people's boxes.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent 52cef755

fs/notify/inotify/inotify_fsnotify.c

+31 −2
Original line number Original line Diff line number Diff line
@@ -105,16 +105,45 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode 
	return send;

	return send;

}

}





/*

 * This is NEVER supposed to be called.  Inotify marks should either have been

 * removed from the idr when the watch was removed or in the

 * fsnotify_destroy_mark_by_group() call when the inotify instance was being

 * torn down.  This is only called if the idr is about to be freed but there

 * are still marks in it.

 */

static int idr_callback(int id, void *p, void *data)

static int idr_callback(int id, void *p, void *data)

{

{

	BUG();

	struct fsnotify_mark_entry *entry;

	struct inotify_inode_mark_entry *ientry;

	static bool warned = false;



	if (warned)

		return 0;



	warned = false;

	entry = p;

	ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);



	WARN(1, "inotify closing but id=%d for entry=%p in group=%p still in "

		"idr.  Probably leaking memory\n", id, p, data);



	/*

	 * I'm taking the liberty of assuming that the mark in question is a

	 * valid address and I'm dereferencing it.  This might help to figure

	 * out why we got here and the panic is no worse than the original

	 * BUG() that was here.

	 */

	if (entry)

		printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n",

			entry->group, entry->inode, ientry->wd);

	return 0;

	return 0;

}

}





static void inotify_free_group_priv(struct fsnotify_group *group)

static void inotify_free_group_priv(struct fsnotify_group *group)

{

{

	/* ideally the idr is empty and we won't hit the BUG in teh callback */

	/* ideally the idr is empty and we won't hit the BUG in teh callback */

	idr_for_each(&group->inotify_data.idr, idr_callback, NULL);

	idr_for_each(&group->inotify_data.idr, idr_callback, group);

	idr_remove_all(&group->inotify_data.idr);

	idr_remove_all(&group->inotify_data.idr);

	idr_destroy(&group->inotify_data.idr);

	idr_destroy(&group->inotify_data.idr);

}

}